A heart valve may become defective or damaged, such as resulting from congenital malformation, disease, or aging. When the valve becomes defective or damaged, the leaflets may not function properly. One common problem associated with a degenerating heart valve is an enlargement of the valve annulus (e.g., dilation). Other problems that may result in valve dysfunction are chordal elongation and lesions developing on one or more of the leaflets.
The bicuspid or mitral valve is located in the left atrioventricular opening of the heart for passing blood unidirectionally from the left atrium to the left ventricle of the heart. The mitral valve is encircled by a dense fibrous annular ring and includes two valve leaflets of unequal size. A larger valve leaflet, which is known as the anterior leaflet, is located adjacent the aortic opening. The smaller leaflet is the posterior leaflet.
When a mitral valve functions properly, for example, it prevents regurgitation of blood from the ventricle into the atrium when the ventricle contracts. In order to withstand the substantial backpressure and prevent regurgitation of blood into the atrium during the ventricular contraction, the cusps are held in place by fibrous cords (cordae tendinae) that anchor the valve cusps to the muscular wall of the heart.
By way of example, if an annulus enlarges or dilates to a point where the attached leaflets are unable to fully close (malcoaptation), regurgitation or valve prolapse may occur. Adverse clinical symptoms, such as chest pain, cardiac arrythmias, or dyspnea, may manifest in response to valve prolapse or regurgitation. As a result, surgical correction, either by valve repair procedures or by valve replacement, may be required.
Surgical reconstruction or repair procedures may include plication, chordal shortening, or chordal replacement. Another common repair prodecure relates to remodelling of the valve annulus (e.g., annuloplasty), which may be accomplished by implantation of a prosthetic ring to help stabilize the annulus and to correct or help prevent valvular insufficiency which may result from defect or dysfunction of the valve annulus. Properly sizing and implanting the annuloplasty ring can substantially restore the valve annulus to its normal, undilated circumference. In situations where the valve leaflets exhibit lesions, it also may be necessary to reconstruct one or more valve leaflets by securing grafts or patches to the leaflets, such as over lesions or holes formed in the leaflet. The repair or reconstruction of the leaflets may be complicated and time consuming, the results of which are not readily reproducible.